1. Field of the Invention
The present invention is related to electric power systems, and more particularly to a method and apparatus for integrating a DC current sensor with a DC inductor.
2. Description of the Related Art
DC current sensors are essential components for many electric power systems. DC current sensors determine current magnitude and direction at various circuit locations; facilitate proper control, protection and/or monitoring of the overall electrical system; etc. In particular, in a More Electric Aircraft (MEA) architecture, a large number of stand-alone current sensors are used, in addition to various common-mode and differential-mode inductors, as required for the power topology and/or for proper Electromagnetic Interference (EMI) and Power Quality mitigation.
Typical/conventional standalone current sensors and inductors are heavy and expensive, and need to be used together with bus-bars, cables, and other mounting fixtures inside a circuit. For each typical/conventional current sensor employed in an electric power system, the system is disturbed at two different places, where the current sensor contacts are connected to the electric power system. Hence, installation of typical/conventional current sensors in electric power systems causes significant disturbances. Typical/conventional current sensors also require proper thermal management. Hence, additional parts are needed with typical/conventional current sensors, which reduces reliability and adds extra weight, volume, cost and complexity to electrical circuits.
Disclosed embodiments of this application address these and other issues by integrating a DC inductor/choke with a current sensor, or by modifying a DC inductor to measure DC current in the same integrated package. Methods and apparatuses of the present invention implement the functions of inductor and current sensor in one integrated package. In one embodiment, a DC inductor is combined with an integrator, a gain control circuit, and a feedback loop, to obtain an integrated DC inductor/current sensor that performs both inductive and current sensing functions. The integrated DC inductor/current sensor outputs a voltage proportional to an input current through the inductor, or a current equal to the input current through the inductor. In another embodiment, a DC integrated inductor/current sensor includes two windings around a magnetic core, and outputs a current equal to the current through a first winding, and/or a voltage proportional to the current through the first winding. In other embodiments, typical/conventional current sensors are integrated with DC inductors into one package. The integrated DC inductor/current sensors of the current invention have wide current/temperature operating range, are lightweight and cost-effective, and provide highly accurate current measurements.